The following are some questions and answers about the Iraqi tribunal trying Saddam and seven others defendants:
Who is trying Saddam?
Saddam and his co-defendants are being tried before what was originally called the Iraqi Special Tribunal, established in December 2003 by US-led occupation authorities. It became known as the Iraqi High Tribunal in October and consists of two trial chambers with five judges in each.
The chief judge is Raouf Abdel-Rahman, who replaced Rizgar Amin after he resigned in protest over what he said was government interference with the court.
Who brought the charges?
The tribunal has 20 investigative judges, led by a chief investigator, who gather evidence against suspects. Once an investigator has gathered evidence, including depositions from witnesses, he presents his case to the chief investigator.
If he gives the go-ahead, the case file is presented to the trial judges, who decide whether there is enough evidence to proceed.
In Saddam's case, the evidence about the killing of more than 140 Shia Muslims from Dujail village, north of Baghdad, after a 1982 attempt on the former president's life, was gathered by chief investigative judge Raad Jouhi.
The case against Saddam and the others was presented in court by the chief prosecutor.
Who is defending Saddam and the others?
Saddam has a small team of defence lawyers led by Khalil al-Dulaimi, an Iraqi with little experience in major criminal cases, especially those involving allegations of crimes against humanity.
The other defendants are represented by an array of Iraqi lawyers. Since the trial began on 19 October, gunmen have killed two defence lawyers and wounded a third, who has fled the country.
Former US Attorney General Ramsey Clark and Najeeb al-Nauimi, former justice minister of Qatar, joined the defence at the last minute as international observers.
If found guilty, can Saddam appeal?
Yes. The tribunal has a nine-member appeals chamber.
According to the tribunal statutes, any sentence handed down by the trial judges must be carried out within 30 days of all appeals being exhausted. The charges in the Dujail case carry a maximum sentence of death, which is by hanging in Iraq.
Will Saddam see the witnesses?
The marble-lined courtroom provides for a screen to be drawn to protect the anonymity of some witnesses. Observers view the court from behind security glass. Television coverage is transmitted with at least a 30-minute delay.
How long will the Dujail trial last?
Some officials say the trial may take several more months.
The appeals process may also last months.
Will Saddam be tried for other charges?
Yes, the general prosecutor has already charged Saddam with mass murder against Iraqi Kurds.